Effects of pH, phosphate and ammonia on the rate of uptake of nitrate and ammonia by freshwater phytoplankton

Toetz, Dale W.

doi:10.1007/bf00014029

Cited by 13 publications

(5 citation statements)

References 10 publications

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“…Concerning nitrate, the lack of impact of seawater acidification alone is similar to the response reported for freshwater phytoplankton [89] , for pH T s ranging between 6.6 and 9.2. Conversely, in some marine macroalgae, some authors [90] – [92] observed an enhancement of nitrate uptake at high CO 2 levels due to an increase in the activity of the nitrate reductase.…”

Section: Discussionsupporting

confidence: 81%

Coral Uptake of Inorganic Phosphorus and Nitrogen Negatively Affected by Simultaneous Changes in Temperature and pH

et al. 2011

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The effects of ocean acidification and elevated seawater temperature on coral calcification and photosynthesis have been extensively investigated over the last two decades, whereas they are still unknown on nutrient uptake, despite their importance for coral energetics. We therefore studied the separate and combined impacts of increases in temperature and pCO2 on phosphate, ammonium, and nitrate uptake rates by the scleractinian coral S. pistillata. Three experiments were performed, during 10 days i) at three pHT conditions (8.1, 7.8, and 7.5) and normal temperature (26°C), ii) at three temperature conditions (26°, 29°C, and 33°C) and normal pHT (8.1), and iii) at three pHT conditions (8.1, 7.8, and 7.5) and elevated temperature (33°C). After 10 days of incubation, corals had not bleached, as protein, chlorophyll, and zooxanthellae contents were the same in all treatments. However, photosynthetic rates significantly decreased at 33°C, and were further reduced for the pHT 7.5. The photosynthetic efficiency of PSII was only decreased by elevated temperature. Nutrient uptake rates were not affected by a change in pH alone. Conversely, elevated temperature (33°C) alone induced an increase in phosphate uptake but a severe decrease in nitrate and ammonium uptake rates, even leading to a release of nitrogen into seawater. Combination of high temperature (33°C) and low pHT (7.5) resulted in a significant decrease in phosphate and nitrate uptake rates compared to control corals (26°C, pHT = 8.1). These results indicate that both inorganic nitrogen and phosphorus metabolism may be negatively affected by the cumulative effects of ocean warming and acidification.

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Section: Discussionsupporting

confidence: 81%

Coral Uptake of Inorganic Phosphorus and Nitrogen Negatively Affected by Simultaneous Changes in Temperature and pH

et al. 2011

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“…The threshold for the effect of ammonium on nitrate uptake is quite variable, ranging in cultures from 0.1 to 90 LIM (Table 5 ) , and in the field from 0.1 to 15 CIM (Kuenzler et al 1979, Toetz 1981, Paasche & Kristiansen 1982, Berman et al 1984, Prjscu & Priscu 1984, Probyn 1985, Lipschultz et al 1986, Queguiner et al 1986, Pennock 1987. Considerable variation would be expected in thresholds because they probably result from a number of interacting biochemical processes (but the cause is currently unknown) and they are defined differently in various studies.…”

Section: Analysis Of Existing Data On Inhibitionmentioning

confidence: 99%

The interaction between ammonium and nitrate uptake in phytoplankton

Dortch¹

1990

Mar. Ecol. Prog. Ser.

667

416

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ABSTRACT. A basic tenet of nitrogen utilization in phytoplankton is that ammoniuln inhibits nitrate uptake. Consequently, it is generally believed that little or no nitrate uptake occurs at ammonium concentrations above ca 1 yM. A thorough review of field studies shows that the reduction of nitrate uptake rate in the presence of ammonium is rarely so severe, and that it is a highly variable phenomenon. To simplify quantification of the interaction between nitrate and ammonium uptake, it is proposed that it be divided into an indirect interaction, preference, and a direct effect, inhibition. In order to determine preference and inhibition it is necessary to measure uptake of each inorganic nitrogen source alone and in the presence of increasing concentrations of the other nitrogen source. Preference for ammonium uptake is manifested primarily in a higher V,,,,, and lower K, for ammonium uptake than for nitrate uptake and is accentuated by low light and low nitrogen availability. However, although ammonium is the preferred nitrogen source for uptake, growth rates on nitrate usually equal or exceed those on ammonium. Inhibition of nitrate uptake by ammonium is much more variable, but when separated from preference is less extreme. It is also enhanced by low light, but unlike preference, i t is greater when phytoplankton are N sufficient. Species differences are apparent for both preference and inhibition, but there are only enough data for preference to determine how it varies among algal groups. Finally, there are reports of low concentrations of ammonium stimulating nitrate uptake and of nitrate inhibiting ammonium uptake. Such unexpected interactions along with variations in preference and inhibition with species composition and environmental conditions may account for the variability observed in field studies and will not be explainable or predictable until more is known about the underlying biochemical mechanisms. Even though it is not possible at present to model nitrate uptake accurately because of uncertainty about the interaction between ammonluln and nitrate uptake, it is quite evident that the simplistic view that nitrate uptake is reduced to zero if ammonium exceeds 1 1iM would often result in large underestimates of nitrate uptake and new production.

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“…Limnological knowledge and their proper applications for better fish yield and management of the ecosystems are prerequisites to sustainable fish sectoral development and maintenance of the eutrophic nature of the wetland ecosystem (Wetzel 1983). Fish health and management of other biodiversity are practical applications of limnology and aquacultural environment (Khan andChowdhury 1974 andToetz 1971). It is most important to study the interrelationship between the physico-chemical aspects and between phyto-zooplankton and the effect of agricultural effluent on the biota.…”

Section: Introductionmentioning

confidence: 99%

Limnological status of Trimohini Beel of Rajshahi, Bangladesh

Islam

Chowdhury

2014

J. Asiat. Soc. Bangladesh, Sci.

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A total of 38 zooplankton genera and 26 physico-chemical variables were recorded in Trimohini Beel. This beel marked as a medium level of polluted wetland based on the values of the redox characteristics i.e. pH, DO, BOD, COD, Eh and rH 2 , chlorides, nitrites, ammonium, phosphate values etc. and on the presence of some zooplankton as indicator of pollution. A large number of inland fresh water non-culturable fishes and other aquatic biota of the Trimohini Beel may be eliminated in future due to mixing of continuous chemicals from agriculture fields. It is necessary to conserve the ecosystem of Trimohini Beel for the fresh water non-culturable fishes and other aquatic biota.

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Effects of pH, phosphate and ammonia on the rate of uptake of nitrate and ammonia by freshwater phytoplankton

Cited by 13 publications

References 10 publications

Coral Uptake of Inorganic Phosphorus and Nitrogen Negatively Affected by Simultaneous Changes in Temperature and pH

Coral Uptake of Inorganic Phosphorus and Nitrogen Negatively Affected by Simultaneous Changes in Temperature and pH

The interaction between ammonium and nitrate uptake in phytoplankton

Limnological status of Trimohini Beel of Rajshahi, Bangladesh

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